This invention relates in general to communications systems, and more particularly to a method of resolving conflicts between multiple agents in an open standards-based communications system.
The evolution towards the design of multimedia communications systems based on open standards has been ongoing since the 1980s. One example of such a system is the MediaPath(trademark) communications server manufactured by Mitel Corporation. The MediaPath(trademark) system comprises call control software which operates in conjunction with a plurality of server telecommunication boards (voice processing board, trunk board, line board, etc.), as described in http://www.mitel.com/MediaPath (1997).
In R. Buhr, D. Amyot, M. Elammari, D. Quesnel, T. Gray, S. Mankovski, xe2x80x9cFeature-Interaction Visualisation and Resolution in an Agent Environmentxe2x80x9d, edited by K. Kimbler and L. G. Bouma, p.135-149, a multi-agent architecture is set forth wherein each physical device is represented by a device agent that is responsible for handling and controlling all requests and actions of the device. The device agent may contain multiple feature agents, which are responsible for implementing the various features to which the device has subscribed. The end user may also be represented by a user-agent, which contains all of the preferences of the user.
Feature interaction occurs when two or more agents want to apply different policies whose actions or goals conflict. Detecting and resolving feature interactions has been an active area of research (see for example L. G. Bouma, H. Velthuijsen, editors: xe2x80x9cFeature Interactions in Telecommunications Systemsxe2x80x9d, ISO Press, Amsterdam, 1994, 272 pp.; K. E. Cheng, T. Ohta, editors: xe2x80x9cFeature Interactions in Telecommunications IIIxe2x80x9d, ISO Press, Amsterdam. 1995, 223 pp.: P. Dini, R. Boutaba. L. Logrippo, editors: xe2x80x9cFeature Interactions in Telecommunications Networks IVxe2x80x9d. ISO Press, Amsterdam, 1997, 373 pp.: and K. Kimbler and L. G. Bouma. xe2x80x9cFeature Interactions in Telecommunications and Software Systems Vxe2x80x9d, ISO Press. Amsterdam, 1998, 374 pp.). Several approaches to solving the problem of feature interaction are also set forth in A. Aho, N. Griffeth, xe2x80x9cFeature Interactions in the Global Information Infrastructure,xe2x80x9d in Foundations of Software Engineering, Washington, October 1995.
One common aspect to all of the prior art solutions to the problem of feature interaction is that the end user has no control of the outcome of the feature interactions. The systems according to the prior art predefine the result of feature interactions, without taking into consideration the parameters that are relevant to the end user, such as, the source of the call or the time of day. For example, the system disclosed in R. Buhr, et al uses an absolute priority mechanism to resolve conflict between multiple agents. In that system, a PROHIBIT action always take precedence over a FORWARDTO or a PERMIT action, with the result that the end user cannot affect the result of a feature interaction.
According to the present invention, an architecture of multiple agents is provided, based on the negotiating agents"" approach to resolving feature interactions, as set forth in R. Buhr, et al, discussed above and N. Griffeth, H. Velthuijsen, xe2x80x9cThe Negotiating Agents Approach to Runtime Feature Interaction Resolutionxe2x80x9d, in Feature Interactions in Telecommunications Systems, IOS Press, Amsterdam. May 1994. However, according to the present invention, an event-based model is used to detect feature interaction, and fuzzy constraints are applied to the policies that describe the system. A mechanism is established by which the user may add rules or provide the system with parameters that will affect the outcome of any conflict that may occur, thereby giving real control over the conflict to the end user.